From: Eric Biggers <ebiggers@xxxxxxxxxx>
Adjust fscrypt_zeroout_range() to encrypt a block at a time rather than
a page at a time, so that it works when blocksize < PAGE_SIZE.
This isn't optimized for performance, but then again this function
already wasn't optimized for performance. As a future optimization, we
could submit much larger bios here.
This is in preparation for allowing encryption on ext4 filesystems with
blocksize != PAGE_SIZE.
This is based on work by Chandan Rajendra.
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
fs/crypto/bio.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index bcab8822217b0..e67e9d4d342b3 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c
@@ -73,12 +73,12 @@ EXPORT_SYMBOL(fscrypt_enqueue_decrypt_bio);
int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
sector_t pblk, unsigned int len)
{
+ const unsigned int blockbits = inode->i_blkbits;
+ const unsigned int blocksize = 1 << blockbits;
struct page *ciphertext_page;
struct bio *bio;
int ret, err = 0;
- BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
-
ciphertext_page = fscrypt_alloc_bounce_page(GFP_NOWAIT);
if (!ciphertext_page)
return -ENOMEM;
@@ -86,7 +86,7 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
while (len--) {
err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk,
ZERO_PAGE(0), ciphertext_page,
- PAGE_SIZE, 0, GFP_NOFS);
+ blocksize, 0, GFP_NOFS);
if (err)
goto errout;
@@ -96,14 +96,11 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
goto errout;
}
bio_set_dev(bio, inode->i_sb->s_bdev);
- bio->bi_iter.bi_sector =
- pblk << (inode->i_sb->s_blocksize_bits - 9);
+ bio->bi_iter.bi_sector = pblk << (blockbits - 9);
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
- ret = bio_add_page(bio, ciphertext_page,
- inode->i_sb->s_blocksize, 0);
- if (ret != inode->i_sb->s_blocksize) {
+ ret = bio_add_page(bio, ciphertext_page, blocksize, 0);
+ if (WARN_ON(ret != blocksize)) {
/* should never happen! */
- WARN_ON(1);
bio_put(bio);
err = -EIO;
goto errout;
--
2.21.0.593.g511ec345e18-goog
